<!doctype html>
<html>

<head>
  <meta charset="utf-8">
  <title>自动备份设置</title>
  <link href="1.css" type="text/css" rel="stylesheet">
</head>
<script>
  function main() {
    window.location.href = "main.html";
  }
  function save() {
    var show = document.getElementById("show");
    show.innerHTML = "保存成功！";
  }
</script>

<body>
  <h2>自动备份设置</h2>
  <div id="div" class="a">
    <input type="checkbox" checked>开启自动备份<br>
    自动备份间隔时间&ensp;<input type="text" size="1" value="30">天<br>
    <input type="checkbox" checked>开启通讯录更改自动备份
  </div>
  <div>
    <p id="show">&ensp;</p>
    <button onClick="save()" class="c">保存<br>更改</button>
    <div class="c" style="display:inline-block;">&ensp;</div>
    <button onClick="main()" class="c">返回<br>主界面</button>
  </div>
</body>

</html>